Hello Abhishek, 

Previously there used to be only EEE branch then ECE came and now the new one is ECM. ECM is a new brand compared to other branches. So its still on growth but till the time you will pass out the condition will be stable for this branch. Talking about the scope of ECM in future then u can aways apply for, 

• ELECTRICAL SECTOR 
  
• IT SECTOR

The advantage is that you can apply for 2 sector but the disadvantage comes with the government sector because the vacancies are very less compared to other branches.

The future also depends opon the type of college weather is it 1 tier 2nd tier or 3rd tier.

I hope you will find my answer helpful. 

All the best.